The present invention relates to innovative interproximal devices, and more particularly, but not exclusively, dental tapes and flosses produced from modified thermoplastic elastomers. These interproximal devices are shred resistant and coatable with proprietary saliva soluble coatings such as described and claimed in co-pending patent application Ser. No. 60/263,220, filed Jan. 22, 2001. These interproximal devices can be further improved according to the disclosure and claims of pending applications Ser. Nos. 09/330,491, filed Jun. 11, 1999 and 09/368,664, filed Aug. 5, 1999.
Monofilament interproximal devices are described and claimed in U.S. Pat. Nos. Re 35,439; 3,800,812; 4,974,615; 5,760,117; 5,433,226; 5,479,952; 5,503,842; 5,755,243; 5,845,652; 5,884,639; 5,918,609; 5,962,572; 5,998,431; 6,003,525; 6,083,208; 6,148,830; 6,161,555; and 6,027,592, the disclosures of which are hereby incorporated herein by reference. These dental tapes generally have serious shortcomings in gentleness, in delivering coatings during flossing and in being handled easily and conveniently during flossing.
Polytetrafluoroethylene (PTFE) based interproximal devices are described in: U.S. Pat. Nos. 5,209,251; 5,033,488; 5,518,012; 5,911,228; 5,220,932; 4,776,358; 5,718,251; 5,848,600; 5,787,758; and 5,765,576. To date, no commercial versions of these tapes have been coated effectively and cannot be used to deliver active ingredients, interproximally and subgingivally during flossing. Handling during flossing is difficult. Most have to be folded to provide a consumer acceptable edge. Many are plagued with serious dimensional inconsistency problems, as well.
Multifilament, interproximal devices are described and claimed in U.S. Pat. Nos. 5,033,365; 3,943,949; 6,080,481; 5,830,495; 2,667,443; 4,638,823; 4,029,113; 2,772,205; 4,627,975; 4,414,990; 3,699,979; 3,897,795; 3,838,702; 4,776,358; 5,718,251; 5,603,921; 5,558,901; 5,423,337; 5,357,990; 4,986,288; 3,897,795; 3,928,618; 5,433,226 and 4,033,365, which are hereby incorporated herein by reference.
The Hill, et al., patents, namely U.S. Pat. Nos. 4,911,927; 5,098,711, 5,165,913; and 5,711,935; describe compression loaded multifilament flosses. All multifilament interproximal devices pose major consumer problems in the areas of shredding, breaking, etc. It is this shortcoming that was the basis for the commercial success of PTFE and other monofilament devices.
All of the foregoing references are relevant and are hereby incorporated by reference. These references fail to teach or suggest the use of the modified thermoplastic elastomeric (or TPE), monofilament materials of the present invention as dental tapes or flosses. Nor does the prior art teach or suggest the substantial consumer advantages these modified TPE tapes offer over current tapes, as well as over multifilament flosses. These advantages are detailed below.
The present invention relates to modifying thermoplastic elastomer based tapes using molecular orientation to reduce elongation at break below about 50%, along with an elastic limit of less than about 25%. These atypical elastomer properties are attained along with an enhancement of gentleness. These modified TPE dental tapes can be coated with proprietary, substantive, saliva soluble, crystal-free coatings that are totally released during flossing.
This combination of properties makes these modified TPE tapes uniquely qualified as interproximal devices. That is, this modulation of typical elastomer stretching and elastic limit properties allows the modified tape to be coated with substantially crystal-free coatings and to retain these coatings with substantially no flaking during use while releasing substantially all of these coatings into the oral cavity during flossing.
These modified thermoplastic elastomeric tapes release these coatings during flossing while providing a substantive surface for these coatings to adhere to with substantially no flaking. The modified TPE monofilament tapes of the present invention combine the shred resistance and improved interproximal insertion features of monofilament tapes such as the PTFE, bicomponent and homopolymer commercial tapes marketed today, with the xe2x80x9chandxe2x80x9d, mouth feel and xe2x80x9cloadxe2x80x9d delivery attributes of certain commercial multifilament dental flosses.
The innovative thermoplastic elastomeric tapes of the invention bridge the gap between xe2x80x9ctapes and flossesxe2x80x9d and, in fact, replace both commercial tapes such as Gore""s Glide(copyright), JandJ""s Easy Slide(copyright) and Oral-B""s Satin(copyright), along with commercial waxed dental flosses such as JandJ""s REACH(copyright) Waxed Mint Dental Floss.
The broad appeal of these modified thermoplastic elastomeric tapes with saliva soluble coatings to both monofilament tape users and multifilament floss users poses a major advance in interproximal devices that promises to encourage flossing compliance while delivering during flossing a wide range of soft abrasives, cleaners, mouth conditioners, and active ingredients interproximally and subgingivally, with a minimum of shredding and breaking.
Accordingly, the present invention is directed to oriented thermoplastic elastomer based dental tapes extruded with melt spinning extrusions carried out at draw ratios from between about 4:1 and about 7.5:1, and draw temperatures from between about 80xc2x0 and about 265xc2x0 C., wherein said oriented tapes have:
an elongation at break of less than about 50%, and
an elastic limit of less than about 25%,
and where said thermoplastic elastomer is selected from the group consisting of styrenics, olefinic blends, elastomeric alloys, urethanes, copolyesters, polyamides and mixtures and/or copolymers thereof.
Advantageously, the oriented thermoplastic elastomer based dental tapes described herein, have a tape flex-twist index from between about 2.5 and about 5, wherein a processing additive is employed in said melt spinning extrusion.
Advantageously, the processing additive is selected from the group consisting of ultra-high molecular weight polydimethylsiloxanes in organic resin carriers, copolymers, calcium stearate and mixtures thereof.
Advantageously, the organic resin carrier for said processing additive is selected from the group consisting of: polypropylene, polybutylene terephthalate, ethylene maleic acid, high density polyethylene, nylon and mixtures thereof.
Advantageously, the oriented thermoplastic elastomer based dental tapes according to the present invention have:
a. a break strength from between about 10 Newtons and about 40 Newtons,
b. a gentleness perception from between about 5 and about 8,
c. a Shore D hardness from between about 30 and about 40, and
d. a tape flex-twist index from between about 2.5 and about 5.
Advantageously, the thermoplastic elastomer based dental tapes according to the present invention comprise polyamides that are selected from the group of structural formulas consisting of: 
wherein: a=16 to 40, x=10 to 50, and b=16 to 40; 
wherein A is a C19 to C21 dicarboxylic acid and wherein B is:
xe2x80x94(CH2)3xe2x80x94Oxe2x80x94[xe2x80x94(CH2)4xe2x80x94Oxe2x80x94]vxe2x80x94(CH2)3xe2x80x94
and wherein n, v, w, y and z are whole numbers; and 
where PA represents the polyamide segment and PE the polyether segment and n is a whole number.
Advantageously, the oriented thermoplastic elastomer based dental tapes according to the present invention comprise a polyamide having the structural Formula 1: 
wherein: a and b=16 to 40 and x=16 to 50.
Advantageously, the oriented thermoplastic elastomer based dental tapes according to the present invention comprise a thermoplastic elastomer which is a polyamide having the structural Formula 2: 
wherein w and z are whole numbers.
Advantageously, the oriented thermoplastic elastomer based dental tapes according to the present invention comprise a thermoplastic elastomer that is a polyamide having the structural Formula 3: 
wherein
A=C19 to C21 dicarboxylic acid and
B=xe2x80x94(CH2)3xe2x80x94Oxe2x80x94[(CH2)4xe2x80x94Oxe2x80x94]vxe2x80x94(CH2)3xe2x80x94.
Oriented thermoplastic elastomer based dental tapes according to claim 1, wherein said thermoplastic elastomer is a polyamide having the structural Formula 4: 
wherein n, y and w are whole numbers.
Advantageously, the thermoplastic elastomer is a polyamide having the structural Formula 5: 
where PA represents the polyamide segment and PE the polyether segment and n is a whole number.
Another embodiment of the present invention is a method for the melt spinning extrusion of oriented thermoplastic elastomer based dental tapes comprising the steps of:
a. melting said thermoplastic at melt temperatures ranging from between about 170xc2x0 C. and about 300xc2x0 C.,
b. compressing said melt through suitable sized tape-shape holes in a melt spinning extruder,
c. taking up said tape at a spinning speed while passing said tape through a cooling bath, and
d. drawing said cooled tape at draw ratios from between about 4:1 and about 7.5:1 at draw temperatures from between about 80xc2x0 C. and about 265xc2x0 C.
Advantageously, the method according to the present invention further utilizes a melt spinning extruder wherein said tape-shaped holes are selected from holes having a width from between about 1.05 mm and about 2.15 mm and a thickness from between about 0.05 mm and about 0.09 mm and tapes produced from these holes have a decitex from between about 700 and about 1700.
Advantageously the oriented thermoplastic elastomer based dental tapes according to the present invention have an elastic limit up to about 15%.
Advantageously the oriented thermoplastic elastomer based dental tapes according to present invention have a tape flex-twist index from between about 2.5 and about 5.
Advantageously the oriented thermoplastic elastomer based dental tapes according to the present invention may be coated with substantive, saliva soluble, crystal-free coatings that are substantially flake-free, wherein said coatings are substantially totally released interproximally and subgingivally during flossing.
Advantageously, the oriented thermoplastic elastomer based dental tapes according to the present invention may be used to deliver substantive, flake-free, saliva soluble coatings to interproximal and subgingival sites during flossing.
Advantageously, the oriented thermoplastic elastomer based dental tapes according to the present invention may be coated with substantive, crystal-free coatings having Shore D hardness substantially lower than commercial dental tapes.
Another embodiment of the present invention comprises a method of treating interproximal and subgingival areas in the oral cavity comprising flossing said areas with an oriented thermoplastic based dental tape having an elongation at break of less than about 50% and an elastic limit up to 25%, wherein said tape is coated with substantive, crystal-free coatings that are substantially flake-free and totally released from said tape during flossing.
Another embodiment of the present invention comprises providing an oriented thermoplastic elastomer based dental tape having a color throughout selected from the group consisting of green, blue, aqua, orange and purple.